GOALI: Manufacturing Large, Diamond Single Crystals via High-Pressure, High-Temperature Growth

该学术联络机会奖（GOALI）支持为钻石单晶制造提供新知识的研究，促进科学发展，促进国家繁荣、健康和安全。金刚石单晶长期以来一直被视为珍贵的宝石，但由于其独特的性质，在新技术应用方面也显示出巨大的希望。虽然天然钻石是由地壳中深度超过100英里的碳形成的，但这些条件可以在实验室中模拟，从而使用高压、高温生长过程制造出最高质量的人造钻石晶体。这笔拨款支持基础研究，以改进这一过程，使单晶钻石可以以更大的尺寸、超高质量和更低的成本制造，从而使高功率x射线系统的光学元件，以及核反应堆和医疗应用、电力电子和量子计算中的辐射探测器设备的应用成为可能。研究结果将对经济竞争力和国家安全产生积极影响。这项研究涉及多个学科，包括先进制造、计算建模、晶体生长和材料科学。多学科方法有助于扩大参与，并对工程教育产生积极影响。用于生长大型单晶的制造工艺必须达到原子级结构的完美，同时保持足够高的产量以满足成本目标。该项目通过在高压、高温系统中晶体生长来生产单晶金刚石。这个系统有能力生长出最高结晶质量的钻石。然而，极端的压力（5 GPa）和温度（1500 K）使得直接的原位生长诊断变得不可能，并且建模是工艺改进的重要工具。该项目开发并应用了基于热力学、动力学和输运的新型计算模型，以更好地了解高压、高温系统中单晶金刚石生长的基本机制。这些模型通过GOALI合作伙伴Euclid Beamlabs， LLC进行的生长实验进行了验证，并应用于改善制造结果，如大晶体尺寸和提高生长速率。一个重要的目标是避免导致夹杂物的工艺条件，夹杂物是在生长过程中含有金属溶剂的微米级缺陷。多尺度模型描述了原子高度的步骤，这些步骤在生长中的钻石的各个方面移动，并预测等距离的步骤何时不稳定地形成束，从而触发包裹体的形成。因此，了解聚束的开始，可以通过建模和实验来评估创新的生长策略，例如系统的时间依赖性倾斜。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This Grant Opportunities for Academic Liaison with Industry (GOALI) award supports research that contributes new knowledge related to diamond single crystal manufacturing, promoting science and advancing national prosperity, health, and security. Diamond single crystals have long been prized as gemstones but have also shown great promise for new technical applications because of their unique properties. While natural diamonds are formed from carbon in the earth’s crust at depths greater than 100 miles, these conditions can be mimicked in the laboratory allowing synthetic diamond crystals of the highest quality to be manufactured using the High-Pressure, High-Temperature growth process. This grant supports fundamental research to improve this process so that single-crystal diamonds can be manufactured in larger sizes, at ultra-high quality, and for less cost, thus enabling application in optical elements for high-power X-ray systems, as well as in devices for radiation detectors in nuclear reactors and medical applications, power electronics, and quantum computing. Results from this research will favorably impact economic competitiveness, and national security. This research involves several disciplines including advanced manufacturing, computational modeling, crystal growth, and materials science. The multi-disciplinary approach helps broaden participation and positively impacts engineering education.Manufacturing processes employed to grow large, single crystals must achieve atomic-level structural perfection while simultaneously maintaining yields that are high enough to meet cost objectives. This project addresses the production of single-crystal diamond via crystal growth in a High-Pressure, High-Temperature system. This system has the capability to grow diamonds of the highest crystalline quality. However, extreme pressure (5 GPa) and temperature (1,500 K) make direct, in situ diagnostics of growth impossible and modeling a vital tool for process improvement. This project develops and applies novel computational models based on thermodynamics, kinetics, and transport to better understand the fundamental mechanisms responsible for single-crystal diamond growth in the High-Pressure, High-Temperature system. These models are validated via growth experiments conducted by GOALI partner, Euclid Beamlabs, LLC, and applied to improve manufacturing outcomes, such as large crystal size and increased growth rate. An important goal is to avoid process conditions leading to inclusions, which are micron-sized defects containing metallic solvent trapped during growth. Multi-scale models describe steps of atomic height that move across the facets of the growing diamond and predict when an equidistant train of steps destabilizes to form bunches, triggering inclusion formation. Understanding the onset of bunching thus allows innovative growth strategies, such as time-dependent tilting of the system, to be assessed by modeling and tested using experiments.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.